I'll use ∩ to represent arc since I have no arc symbol
LEFT SIDE IS STATEMENT RIGHT SIDE IS REASON
1. m∩AB = m∩CD given
2. OA = OC, OB = OD radii of same circles are =
3. ∡1 = ∡2 If arcs are =, then central angles are =
3. ΔAOB ≅ΔDOB SAS
4. AB = CD CPCTE
